Automatic pouring ladle



Sept. 17, 1957 J. H. KEATING AUTOMATIC POURING LADLE 4 Sheets-Sheet 1 IN V EN TOR.

BY JOHN H. KEATING Sept. 17, 1957 .1. H. KEATING AUTOMATIC POURING LADLE 4 Sheets-Sheet 2 Filed Jan. 24, 1955 INVENTOR.

JOHN |-|v KEATING Sept. 17, 1957 J. H. KEATING AUTOMATIC POURING LADLE Filed Jan. 24, 1955 4 Sheets-Sheet 4 INVENTOR. JOHN H KEATING ATTORNEYS n t d r P t n AUTOMATIC POURING LADLE Application January 24, 1955, Serial No. 483,706

9 Claims. (Cl. 22-82) This invention relates to apparatus for automatically pouring molten metal into molds, and particularly to apparatus for automatically pouring non-ferrous molten metal into molds of varying volumetric capacity which are mounted on a conveyor that brings them to the apparatus and takes them away after they have been filled.

In high production non-ferrous foundries, it is known to mount molds on conveyors, so that each mold is consecutively carried beneath a pouring ladle to be charged. The conveyor travels intermittently, stopping when each mold is positioned beneath the pouring ladle, and moving on when a mold has been filled to take the filled mold away from the ladle and replace it with an empty mold. The cycle is continuous and before a charged mold once again reaches the pouring station it is opened, the cast article is removed, and the mold is made ready for recharging.

In the mass production of large numbers of a single piece, the molds on the conveyor are identical, and usually as many molds are mounted on the conveyor as possible. However, for short runs of differently shaped workpieces it is sometimes economical to build but one mold for each workpiece, so that one conveyor may carry a multiplicity of molds of different sizes and shapes to produce several difierent size castings. As each mold is conveyed to the pouring station, it has been the practice for a workman to stand ready to charge the mold with the proper amount of metal from a hand ladle filled with molten metal dipped from a nearby reservoir.

This method of making castings has many disadvantages. Hand pouring of molds is wasteful since the operation depends on the workmans judgment. If he underfills a mold, the casting will be defective, and if he over fills a mold, metal is wasted. The workmans judgment varies with his fatigue and the pouring of the metal therefore is not necessarily done uniformly. There is a correct distance for the molten metal to drop and a set rate for it to fall. This reduces turbulence and gives a sounder and denser casting. Positive control of pouring reduces scrap and improves the castings. The workman must be given time to refill his ladle between each pouring, which is time consuming and requires slowing down the speed of the conveyor to a rate with which the workman can keep up. Furthermore, due to the heat which is given off from'the adjacent reservoir, ladle and molds, the length of exposure to this heat which a workman can stand comfortably is relatively short, requiring him to take frequent rest periods.

To overcome the above and other problems involved in making short runs of castings of various sizes, it is a general object of this invention to provide pouring apparatus which will automatically pour the correct amount of metal into each mold irrespective of differences in volumetric capacity from one mold to another.

Other objects of the invention include the provision of pouring apparatus which can readily be pre-set sequentially to fill a series of molds of different capacities, and which can be adjusted at'will to bypass molds that are not to be filled or to vary the amount of metal into the molds; the provision of automatic pouring apparatus which is inexpensive to manufacture, install, maintain, and operate and yet which is rugged, dependable and eflicient; the provision'of timing means for controlling the intermittent pouring cycle of the pouring apparatus; the provision of novel means for intermittently tipping the pouring ladle of the apparatus; the provision of novel means for refilling the pouring ladle so that the apparatus may be adapted for use with an open crucible as well as a continuous melting type furnace; the provision of novel means to synchronize the tipping of the pouring ladle with the movement of the molds; and the provision of novel means to synchronize the ladle tipping cycle with the ladle re-filling cycle.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims; the annexed drawings and the following description setting forth in detail certain structure embodying the invention, such disclosed means constituting, however, but one of the various forms in which the principle of the invention may be used.

Figure 1 is a side elevation of the ladle tipping means employed in a preferred embodiment of the invention,

Figure 2 is a sectional view of the two-way solenoid operated air valve employed in the ladle tipping means shown in Figure 1,

Figure 3 is .a side elevation of the mot-or, gear reduction and crank means employed in driving the apparatus of the present invention,

Figure 4 is a side elevation of the ladle refilling mechanism employed in conjunction with the pouring mechanism shown in Figure 1,

Figure 5 is a schematic diagram of the electrical circuit employed to regulatethe pouring cycle of the apparatus shown in Figure 1,

Figure 6 is a schematic diagram of the electrical circuit employed to synchronize the pouring and refilling cycles of the ladles shown in Figures 1 and 4,

Figure 7 is a schematic perspective view of cam shaft means which may be used for actuating the switches employed in the electrical circuit shown in Figure 5, and

Figure 8 is a schematic plan view of a turntable type mold conveyor used in conjunction with a preferred embodiment of the invention.

Referring now to the drawings in greater detail and in particular to Figures 1 and 8, a preferred embodiment of the invention comprises a continuous mold conveyor 1, having a plurality of molds 2 secured thereto, and a plurality of cams 3 also secured to the conveyor adjacent respective molds. Associated in combination with the conveyor is a pouring mechanism having a base 10 and a boom 12 pivotally secured to the apex 14 of the base 10 by means of a pair of lugs 16 depending from the underside of the boom. The lugs 16 are pivotally secured to the apex 14 of the base 10 by means of a threaded fastening 18. The upper end 20 of the boom 12 is adapted to extend outwardly over a turntable or other form of conveyor (not shown) having thereon a series of molds which pass beneath.

To adjust the upper end 20 of the boom 12 with respect to molds passing beneath, a turnbuckle 22 is secured between the base 10 and the lower end 24 of the boom by means of a lug 26 integrally secured to the base 10, and a lug 28 integrally secured to the underside of the boom.

A ladle supporting bracket 30 is secured rigidly to the top end 20 of the boom 12 and is' adapted to receive trunnions32 of a pouring ladle 34 in U-shapedsaddle' blocks 36 which enable the trunnions to pivot freely there-' in and the ladle to tilt. A tilting lever 38 operated as hereafter described is rigidly secured to one of the ladle trunnions. 32 and extends upwardly therefrom.

A two-way pneumatic power cylinder is fixedly mounted on the top side of the lower end 24 of the boom 12, together with a pilot valve 42 and. pilot valvesolenoidactuating means 44. The cylinder 40:is.coupled toJoil filled cylinder dash pot. 46 that causes a piston48: of the pneumatic cylinder to move smoothly at all times to transmit power evenly by means of a connecting'r0d'50.

to the tipping lever 38 of the pouring ladle 34-. The length of theconnecting rod. 50. is adjusted by means of a turnbuckle 52. similar 'tothe turnbuckle 22 used for adjusting the inclination of the boom 12.

Tohold the metal in liquid form, a gas supply. pipe. is provided adjacent the ladle 34 so that a. gas flame may be kept playingv on the base. of the ladle while molten metal is carried in it. In this way, the metal will. be maintained in. its molten state without unnecessary congealing and sticking to the inner. surface of the ladle. Turnbuckle 22 is used to adjust. the inclination. of the boom, as. aforesaid, and once the boom is set, the inclination is not disturbed. during a given run of molds on a particular turntable or conveyor.

Any suitable supply of air under pressure may. be provided to actuate the two-way pneumatic power cylinder 40 and, in the particular embodiment, the pilot valve 42 shown in Figure 2 has been found to be satisfactory. This mechanism comprises the solenoid 44 which mechanically urges the piston 54 (Figure 2) to the left to compress the spring 56 housed in the cylinder adjacent the end 58 of the piston. With the piston in this position, air under pressure is admitted into the cylinder through center port 60 and will pass out through port 62 and line 66 (Figure 1) into the cylinder 40 at its lower end 64. When the solenoid 44 is deenergized, by means to be more fully described hereinafter, the energy of the compressed spring 58 will force the piston 54 to the right to close port 62 and open port 68. Air under pressure from line 70, connected to port 60, will then pass out of port 68 through line 72 into the left side of pneumatic cylinder 40 (Figure l) to draw the connecting rod 50 downwardly and to the right thereby leveling the ladle 34.

The means for controlling the ladle tipping apparatus shown in Figure l is laid out schematically in Figure 5. For every mold which passes beneath the ladle for filling, a timer 74 of conventional construction is added to the wiring circuit. The circuit as shown is set up consecutively to charge eight molds on a conveyor, each of which is of a different volumetric capacity, therefore requiring a different period during which the ladle will be tipped by the mechanism mounted on the boom 12 as shown in Figure 1. Any suitable timing mechanism may be employed which will close a circuit to energize the described ladle tipping means for a predetermined number of sec onds and then automatically break the circuit and reset itself. The timers 74, shown in Figure 5', are manually set by means of timing arms 76 which may be turned to provide any selected period of operation in seconds as shown on the dial face 78 of the timer. The dial hand 80 is spring-urged to follow the timer arm as it is revolved or adjusted clockwise. Thus, the normal position for the hand 80 is in abutting contact with pad 82 of the timer arm. The timer arm 76 itself remains in place where manually set and is adjustable by a slight pressure applied to the arm in either direction.

Thus, it will be seen that consecutive timers 74, shown in Figure 5, may be set, for example, to control periods of approximately four, six, three, eleven, two, fourteen and three seconds, respectively. The dial face 78 of the first timer has been removed to show diagrammatically the synchronous motor '84, contacts 86, and leads 88 which are usually embodied in such devices. In each of the timer circuits, when a relatedtwo pole single throw switch 90 is closed, as will be explained hereinafter, a

circuit is-completed across synchronous motor 84 through in Figure 5, then these molds will receive charges from the ladle which in each case will pour for the number of seconds shown on the corresponding faces of the timers.

A micro-switch 94 is mounted at the base of the mold turntable and is adapted to be actuated by arms (not shown) adjacent each mold station on the turntable so that the switch 94 will be closed each time a mold passes by the location of the switch. A series of double pole single throw switches are provided, one for each timing mechanism 74 and are adapted to be closed in a predetermined sequential order.

Any suitable means may be employed for closing the switches 90 in such sequential order, for example, a series of cams 96 (see Figure 7) on a cam shaft 98, eachcam corresponding to and engaging with one of the switches 90. A ratchet wheel 100 is mounted on one end of the cam shaft 98, and a pawl 102 is adapted to be actuated through a toggle link mechanism by a plunger 104 of a solenoid 106. Each time an arm on the turntable engages and closes switch 94, solenoid 106 is energized to operate the pawl 102 and advance the wheel clockwiseone notch. When the solenoid 106 is deenergized a spring return restores the solenoid plunger to its original position withdrawing the pawl 102 from engagement with wheel 100 and positioning it to engage the next tooth 108 when the solenoid is again energized. The teeth on the rachet wheel are thus so arranged that every engagement of the pawl 102 and a tooth 108 will rotate cam shaft 98 to disengage one switch 90 and bring a second switch 90a (Figure 7) into closed contact. The timers 74 are connected in series so that the closing of any timer switch 90 will complete a circuit across the corresponding timer and a parallel circuit across the pilot valve solenoid 44 (Figure 2).

A pair of 110 volt lines 114 and 116 supply current to the system and are controlled by a master switch 118 in line 114. Current for the solenoid 106 is tapped oil? from lines 114 and 116, and when the master switch 118 is closed and the microswitch 94, adjacent the turntable, is closed by a mold station arm, then the ratchet 100 and pawl 102' cooperate to index the cam shaft 98- one position to close one of the eight switches 90. Current then passes from line 116 through arm 120 of switch 90, along line 92, across timer 74, and then back through line 114. Parallel current passes through arm 122 of switch 90, through line 124 to solenoid 44, a counting mechanism 126, and a pilot light 128, which three units are in parallel with each other. Timers 74 are connected in series between line and 114. Each timer is provided with a pilot light 132, and each switch 90 is provided with a separate toggle switch 134 which is manually operable to disengage any particular timer or any number of timers from the circuit when their corresponding molds are not to be filled upon reaching the pouring station.

The apparatus described hereinabove has been found to be very satisfactory for use in combination with continuous melting furnaces such as described more fully in my co-pending application Serial No. 442,661, entitled Method and Apparatus for Continuously Melting Metal, filed July 12, 1954. The furnace described in this copending application is elevated above the foundry floor and inclined downwardly toward endless conveyors. The lower end of the furnace is provided with a spout positioned above the mechanically-operable pouring ladle 34 of the present invention, so that a continuous flow of metal is maintained to respective pouring ladles by force of gravity alone. Thus, in Figure '1 there will be .pro-

vided a spout, not shown, that continuously pours a small stream of molten metal from above into ladle 34 to keep it full enough to fill each mold even though it is constantly being tipped and partially emptied to fill a given mold. Overflow means, such as a back spout 136 (Figure l) is provided to compensate for any overflow of metal into the ladle.

A second embodiment of mechanism for supplying ladle 34 is adapted for use in conjunction with open crucible melting means as contrasted with the furnace described in my co-pending application. As shown in Figure 4, the level of molten metal 138 in a crucible 140 is con siderably below the pouring ladle 34, and, as aforesaid, it has heretofore been customary to hand dip the metal from the crucible to the molds. To eliminate the hand dipping operation, ladle means 142 is adapted mechanically to ladle the molten metal from the crucible 140 to the pouring ladle 34. This ladle means comprises a socalled pickup ladle 144; a hollow ladle handle or boom 146 integrally secured to the ladle 144, with the interior of the boom communicating with the interior of the ladle; fulcrum means 148 about which the boom 146 is pivotable; and means 150 to pivot the boom 146. The other end of the hollow boom discharges into pouring ladle 34. The boom 146 is hollow throughout and is closed by a plug 152 at the discharge end. A discharge spout 154 is inserted adjacent this end of the boom and positioned over the pouring ladle 34.

t The fulcrum 148 comprises brackets 156 secured to ladle plate 30. The brackets support trunnion bearings on each side of the boom 146 to journal therein boom trunnions 160. The boom 146 pivots on trunnions 160 to lower the ladle 144 tothe dotted line position (Figure 4) into crucible 140, thereby picking up a charge of metal. In the raised position of the pickup ladle 144 (shown in solid lines), the molten metal flows by gravity through the interior of the boom 146 to the discharge spout 154 and into the pouring ladle 34.

The means for pivoting the pickup ladle upwardly and downwardly comprises a motor 162 (see Figure 3); a gear reduction unit 164 coupled to and driven by the motor through a standard flexible coupling 166; an eccentric or crank means 168 rotatably driven by the gear reduction unit 164; and means 170 suitably connecting the eccentric to the pickup ladle boom 146.

Any suitable crank or eccentric means may be used and the eccentric means illustrated in Figures 3 and 4 consists of a circular plate 172 centered and mounted on drive shaft 174 of reduction gear unit 164. A pin 176 is fitted in the plate near its periphery and extends outwardly normal thereto. A connecting rod 178 is pivotally mounted at the lower end to pin 176, and connected at its upper end 180 to the lower end of a cable 182 by thimble and cable clamp means 184. By rotating the plate 172, the connecting rod 178 is provided with a stroke or throw substantially equal to the diameter of the plate. The cable 182 is threaded through any suitable number of pulley blocks 186 and is connected at its other end 185 to an eye plate 187 secured to a bar 190 which is clamped to the boom 146 by pairs of half round clamps 192.

In operation, the pouring ladle 34 is, as described above, tipped intermittently for pre-deterrnined periods of time as controlled by the electrical system shown in Figure and described hereinabove. At the same time that the circuit of Figure 5 is energized by the closing of switch 94, a relay 184 (see modified circuit in Figure 6) is actuated to close a normally open switch (not shown) in the starting circuit of motor 162 thereby to rotate plate 172. In order to synchronize the movements of the two ladles 34 and 144, relay 194 may be a delay timer mechanically similar to timer 74, but adapted to delay energizing motor 162 a suflicient period of time to achieve necessary synchronism between movement of the two ladles.

A normally closed limit switch 196 (see Figures 3 and 4) is positioned at the base of the gear reduction unit 164 and adapted to be opened by a pin 198 projecting inwardly from the plate 172. The limit switch is wired as at 200 to the circuit ofthe motor 162 and is adapted to shut off the motor after one revolution of the plate 172. During this revolution the pickup ladle 144 is dipped into the crucible and thenpivoted upwardly to the position of Figure 4 to allow the metal to flow from the pickup ladle through the hollow handle 146 into the pouring ladle 34.

The limit switch 196 and pin 1% are positioned to make contact with each other just before bottom dead center of the connecting rod is reached. The connecting rod will normally come to rest in this position (see Figure 4) and will thus pass through a complete 360 cycle each time the motor 162 is energized. At the completion of a cycle of operation of the mechanism of Figure 4, all switches automatically reset in readiness for the next cycle of operation. The next and succeeding cycles may be initiated manually or may be initiated automatically from time to time at a rate dependent on the speed with which metal in the ladle 34 is poured.

While I have shown and described a preferred embodiment of the invention, it is contemplated that the invention is susceptible of embodiment in other forms, and is applicable to a variety of situations, without departing from its spirit or scope.

I claim:

' 1. In an automatic pouring and casting device for molten metals including a continuous mold conveyor and a ladle pivotally suspended over said conveyor to fill molds of varying capacity that pass therebelow, the improvement comprising a tipping lever rigidly secured to said ladle, a fluid power cylinder, a connecting rod pivotally secured at one end to said lever and at the opposite end to said fluid power cylinder, a timer for each mold on said conveyor pre-set to operate for a period of time proportionate to the volume of its corresponding mold, means for consecutively energizing each timer responsive to the movement of said conveyor, a power cylinder control valve sequentially operable by said timers and adapted to actuate-said fluid power cylinder, whereby said connecting rod acts through said lever to tip said ladle for predetermined periods of time properly to fill a mold therebelowin accord with its volume.

2. In an automatic pouring and casting device for nonferrous metals including'a mold conveyor and a ladle pivotally suspended over said conveyor to fill each mold as it passes 'therebelow, the improvement comprising an index switch intermittently operated by themovement of said conveyor to actuate a stepping switch solenoid, a bank of switches, one for each mold on said conveyor, said switches being consecutively operable by said stepping switch solenoid, a bank of timers, one for each mold on said conveyor pre-set to operate for a period of time proportionate to the volume of its correspond ing mold, a control valve consecutively operable by said timers and means operable by said control valve to tip said ladle whereby a measured amount of metal will be charged into each mold proportionate to its volumetric capacity.

3. Automatic pouring apparatus for charging molten metals into successive molds of a series comprising a base, a boom pivotally secured to said base, a pouring ladle pivotally secured to one end of said boom, a tipping lever rigidly secured to said ladle, a two-way pneumatic power cylinder secured to said boom, a connecting rod pivotally secured at one end to said lever and at the opposite end to the piston rod of said power cylinder, a solenoid operated pilot valve adapted to operate said power cylinder, a series of timers adapted sequentially to operate said pilot valve and means responsive to the movement of a mold into pouring relation with said apparatus sequentially to actuate said timers.

4. In an automatic pouring device for charging molten metals into successive molds of a series, the improvement in pouring ladle filling means comprising a ladle support pivotally suspending a pouring ladle over a pouring zone adapted to be occupied by a mold, a pickup ladle, a hollow pickup ladle arm secured at one end to said pickup ladle, the interior of said tubular arm communicating with the interior of said pickup ladle, the other end of said arm being positioned over said pouring ladle and pivotally secured to said ladle support; means to pivot said pickup ladle upwardly to discharge molten metal therefrom and then downwardly to refill said ladle, including a flexible cable, eccentric means to reciprocate said cable, and means connecting said cable between said tubular arm and said eccentric means, and means responsive to the movement of a mold conveyor to rotate said eccentric means, whereby simple harmonic motion is intermittently imparted to said pickup ladle.

5. In an automatic pouring device for charging molten metal into molds of varying capacity as they are moved past said device, the improvement comprising a ladle support suspending a pouring ladle over the path of said molds, means for filling said ladle including a pivotally mounted hollow ladle boom, a pickup ladle adapted to dip in a reservoir of molten metal and secured at one end of said boom, the interior of said hollow boom communicating with the interior of said pickup ladle, the other end of said boom being positioned over said pouring ladle, means for pivoting said pickup ladle upwardly to discharge molten metal through said hollow boom into said pouring ladle, means for tipping said pouring ladle to charge the contents of said ladle into a respective one of said molds, means for synchronizing the tipping of said pouring ladle with the movement of said molds, and means for synchronizing the pivotal movement of said pickup ladle with the tipping of said pouring ladle whereby said pouring ladle is filled by said pickup ladle between each mold pouring operation.

6. The device set forth in claim wherein said means for synchronizing the tipping of said pouring ladle with the movement of said molds therebeneath comprises a series of timers, one for each movable mold, switch means associated with said molds sequentially to operate said timers, each of said timers being adapted sequentially to actuate said ladle tipping means when its corresponding mold is stationed beneath said pouring ladle.

7. The device set forth in claim 5, wherein said means for synchronizing pivotal movement of said pickup ladle with the tipping of said pouring ladle comprises an electric circuit including a series of adjustable timers, one for each movable mold, a relay for said pickup ladle, switch means associated with each .of said molds intermittently to operate said timers and said relay, each of said series of timers being adapted sequentially to actuate said ladle tipping means, and said relay being adapted to actuate said pickup ladle pivoting means when said pouring ladle is in a non-pouring position.

8. The device set forth in claim 5, wherein said means for synchronizing pivotal movement of said pickup ladle with the tipping of said pouring ladle comprises an adjustable timer for each of said movable molds, an adjustable timer for said pickup ladle, switch means associated with each of said molds intermittently to operate all of said timers, each of said mold timers being adapted sequentially to actuate said ladle tipping means, said pickup timer being adapted to actuate said pickup ladle pivoting means when said pouring ladle is in a nonpouring position.

9. Mechanism for charging a predetermined volume of molten metal from a ladle into a mold comprising a framework, a supporting boom pivotally mounted adjacent its midsection on said framework, mechanism at one end of said boom to hold the same in adjusted fixed position with respect to said support, a bracket at the other end of said boom including a pair of trunnion journals, a pouring ladle having trunnions in said journals to permit said ladle to tilt, a fluid cylinder with a piston therein mounted on said boom with the cylinder axis extending generally parallel to the boom, a connecting rod adjustable in length extending from the piston to said ladle to tilt said ladle when said piston moves in said cylinder, a damping device secured to said piston to insure its smooth movement in said cylinder, a control valve associated with said cylinder to admit fluid under pressure at either end thereof, timing mechanism adapted to be energized by a mold passing into pouring position beneath said ladle, and a connection between said timing mechanism and said cylinder to control the admission of fluid under pressure to said cylinder to shift said piston and tilt said ladle to charge said mold for a predetermined period of time, and mechanism to reverse said piston and restore said ladle to a non-pouring position.

References Cited in the file of this patent UNITED STATES PATENTS 1,816,059 Smith July 28, 1931 2,023,040 Adams Dec. 3, 1935 2,064,734 Crawford Dec. 15, 1936 2,135,245 Yerkey Nov. 1, 1938 2,363,759 Waldie Nov. 28, 1944 2,459,892 Palmer et a1. Jan. 25, 1949 2,509,079 Trewin et al. May 23, 1950 

